Fatigue crack propagation under block loading analysed in terms of equivalent loading concepts

✍ Scribed by N. Ranganathan; M. Benguediab; C. Nicolas; G. Henaff; J. Petit

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 896 KB
• Volume: 42
• Category: Article
• ISSN: 0013-7944
• DOI: 10.1016/0013-7944(92)90277-l

✦ Synopsis

The results of fatigue crack growth tests under a block loading consisting of four mean levels are analyzed in terms of equivalent constant amplitude loading concepts. The different models used to determine the equivalent loadings are based on the root mean square (RMS) method, a modified method based on Paris' law, Elber's method based on crack closure concepts and a newly proposed energy based method. The results obtained show that the RMS analysis fails under the studied test conditions and leads to highly unconservative life estimates. The modifications brought into Paris' method based on a crack closure analysis lead to very good life estimations. Elber's method also gives good results except for one of the spectra studied. Finally, the experimental energy based method gives excellent results for the studied test conditions.